Mark Zupan went home to Austin, Texas, for 14 hours on Saturday, to attend a buddy's wedding. That was his third weekend at home since April. The star of the documentary "Murderball" has been caught in such a whirlwind of overnight stardom that the latest news -- Eminem wants to play him in a fictional version of the story -- is just one more news item.

PARK CITY, Utah -- I knew you needed leather balls to play rugby, but I didn't know you could also use steel ball bearings. "Murderball," probably the most talked-about documentary at Sundance this year, is about the extreme sport of wheelchair rugby, played in reinforced and armored chairs by quadriplegics with various degrees of disability. It is a full-contact sport.